Terephthalic polyester composition and its use as soil release agent

ABSTRACT

The invention concerns a terephthalic polyester composition (CPT), comprising in mixture: an ethyleneterephthalate homooligomer (PET 1) essentially containing recurrent terephthalate oxyethylene (TE) units; and a block terephthalate copolymer (PET 2/TE-POE) containing at least a polyethyleneterephthalate (PET 2) sequence; and at least a terephthalate polyoxyethylene (TE-POE) sequence whereof the POE unit has a molecular mass of 1500 to 4000 in number; said composition (CPT) being characterised in that: the quantity of (TE) units of (PET 1) represents not more than 10% of the total number of (TE) units present in said composition (CPT); the weight quantity of (TE) units present in the composition (CPT) represents at least 10% of (TE) units present in the composition (CPT); the quantity by weight of mono(oxyethyleneoxy) radicals (OEO) represents at least 1.3% of the weight of the composition (CPT), said radicals (OEO) belonging to the aromatic diester oxyethylene groups (ODA) of formula: —A—C(O)—O—CH2—CH2—O—C(O)—A— present in all the (PET 1) and (PET 2) sequences; and the molar mass by weight of block terephthalic copolymer (PET 2/TE-POE) is at least 30000. The invention also concerns the use of said composition as soil release agent in detergent formulations for washing textiles.

This application is an application under 35 U.S.C. Section 371 ofInternational Application Number PCT/FR991/01691 filed on Jul. 9, 1999.

A subject matter of the present invention is a novel terephthalicpolyester composition, its process of preparation bytransesterification/condensation of poly(ethylene terephthalate) and ofpolyethylene glycol, and its use as soil-release agent in detergentformulations, in rinsing, softening or finishing formulations, for thewashing, with or without pretreatment, the rinsing, the softening or thefinishing of textiles, in particular polyester-based textiles.

The soil-release activity of ethylene terephthalate/polyethylene oxideterephthalate copolymers in the finishing of textiles, in particularpolyester-based textiles, and the use of said copolymers as soil-releaseand/or antiredeposition agents in detergent formulations for thewashing, with or without pretreatment, of textiles, in particularpolyester-based textiles, are well known (U.S. Pat. Nos. 396,252;4,116,885; 4,785,060).

These copolymers can, for example, derive from thetransesterification/condensation of poly(ethylene terephthalate) and ofpolyethylene glycol (U.S. Pat. No. 4,785,060).

The Applicant Company has found a novel terephthalic polyestercomposition which can be obtained by transesterification/condensation ofa poly(ethylene terephthalate) and of a polyethylene glycol and which inparticular exhibits particularly good soil-release properties.

According to the invention, it is a terephthalic polyester composition(TPC) comprising, as a mixture

an ethylene terephthalate homooligomer (PET₁) essentially comprisingoxyethylene terephthalate (TE) repeat units of formula (I)

—C(O)—A—C(O)—O—CH₂—CH₂—O—  (I)

 where A represents the 1,4-phenylene group,

and a block terephthalic copolymer (PET₂/TE-POE) comprising

at least one polyethylene terephthalate block (PET₂) composed ofoxyethylene terephthalate (TE) repeat units of formula (I)

—C(O)—A—C(O)—O—CH₂—CH₂—O—  (I)

 where A represents the 1,4-phenylene group,

and at least one polyoxyethylene terephthalate block (TE-POE) of formula

—C(O)—A—C(O)—O—CH₂—CH₂—O—(CH₂—CH₂—O)_(n)—

 the value of n being such that said block exhibits a number-averagemolecular mass of the order of 1500 to 4000, preferably of the order of3000 to 4000,

said composition being characterized in that:

the amount of (TE) units of the polyethylene terephthalate (PET₁) doesnot represent more than 10%, preferably not more than 7%, of all the(TE) units present in the terephthalic polyester composition (TPC),

the amount by weight of all the (TE) units present in said (TPC)composition represents at least 11%, preferably from 11.5 to 17%, of theweight of said (TPC) composition,

the amount by weight of mono(oxyethyleneoxy) (OEO) residues of formula

_(1/2)O—CH₂—CH₂—O_(1/2)

 represents at least 1.3%, preferably from 1.3 to 2.3%, of the weight ofsaid terephthalic polyester composition (TPC),

said (OEO) residues belonging to the oxyethylene aromatic diester (OAD)groups of formula

—A—C(O)—O—CH₂—CH₂—O—C (O)—A—

 present in all the (PET₁) and (PET₂) blocks,

and in that the weight-average molar mass of said block terephthaliccopolymer (PET₂/TE-POE) is at least 30000, preferably at least 35000,very particularly at least 40000.

The ends of the chains of (PET₁) homooligomers are generally composed of—C(O)—A—C(O)—O—CH₂—CH₂—OH units.

The ends of the chains of block terephthalic copolymer (PET₂/TE-POE) aregenerally composed of

—C(O)—A—C(O)—O—CH₂—CH₂—OH

units and/or

—(CH₂—CH₂—O)_(n−1)—CH₂—CH₂—OH

units.

The characteristics of the (TPC) composition of the invention can bedetermined by subjecting said composition to the following analyses:

size exclusion chromatography (SEC) using a size exclusionchromatography device with simultaneous detection by refractometry andultraviolet, using N,N-dimethylacetamide (DMAc) comprising 10⁻² mol/l ofLiBr as eluent at 100° C.

This measurement (UV chromatography) makes it possible:

to detect the presence of the A (terephthalic) aromatic nuclei,

to determine the percentage of ethylene terephthalate homooligomer(PET₁) in the terephthalic polyester composition (TPC),

to determine the weight-average molar mass of the block terephthaliccopolymer (PET₂/TE-POE), expressed in polystyrene equivalents.

proton nuclear magnetic resonance (¹H NMR) using an NMR spectrometer ina CDCl₃/deuterated hexafluoroisopropanol/deuterated trifluoroaceticanhydride mixture.

This measurement makes it possible to detect

the aromatic (terephthalic T) nuclei,

the oxyethylene units,

the mono(oxyethyleneoxy) (OEO) residues present in the oxyethylenearomatic diester (OAD) groups,

the polyoxyethylene terephthalate blocks (TE-POE), the units at thechain ends.

The calculation makes it possible to deduce therefrom:

the amount by weight of all the (TE) units in the terephthalic polyestercomposition (TPC),

the amount by weight of mono(oxyethyleneoxy) (OEO) residues in theterephthalic polyester composition (TPC).

Further information with regard to these analyses is given in theexamples.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the size exclusive chromatography spectrum of the terephthalicpolyester composition obtained in example 1 herein below; and

FIG. 2 is the size exclusive chromatography spectrum of the terephthalicpolyester composition obtained in comparative example 2 herein below.

Said terephthalic polyester composition forming the subject matter ofthe invention can be obtained by a transesterification/condensationreaction of a polyethylene terephthalate with a weight-average molecularmass of the order of 5000 to 100000, preferably of the order of 10000 to80000, and a polyethylene glycol with a number-average molecular mass ofthe order of 1500 to 4000, preferably of the order of 3000 to 4000,according to a polyethylene terephthalate/(polyethyleneterephthalate+polyethylene glycol) ratio by mass of the order of 11/100to 17/100,+preferably of the order of 11.5/100 to 17/100, in thepresence of an effective amount of condensation catalyst.

Said polycondensation operation being characterized

in that said catalyst is composed of magnesium oxide,

in that, after addition of the polyethylene terephthalate to the moltenpolyethylene glycol, heating the reaction mixture under an inertatmosphere to a temperature of the order of 100 to 150° C., preferablyof the order of 120 to 130° C., the catalyst composed of magnesium oxideis introduced,

in that the temperature of the mixture is brought to a temperature ofthe order of 250 to 290° C., preferably of the order of 270 to 285° C.,

and in that said reaction mixture is subsequently gradually placed undervacuum to a pressure of less than 70000 Pa, preferably of the order of7000 to 130 Pa, while optionally adjusting the temperature to a value ofthe order of 250 to 290° C., preferably of the order of 270 to 285° C.

These temperature and pressure conditions can be maintained for 1 to 5hours approximately, depending upon the equipment used.

The polyethylene terephthalates which can be employed are in particularcommercial products obtained by polycondensation of dimethylterephthalate and of ethylene glycol.

The amounts of magnesium oxide employed can be of the order of 20 to 500ppm, preferably of the order of 100 to 350 ppm.

The reaction mixture can additionally comprise an alkali metal organicsalt, in particular an alkali metal acetate, such as sodium acetate.Said salt can be present according to amounts of the order of 20 to 500ppm, preferably of the order of 100 to 350 ppm.

The terephthalic polyester composition forming the subject matter of theinvention is very particularly advantageous as soil-release agent indetergent formulations, in rinsing, softening or finishing formulations,for the washing, with or without pretreatment, the rinsing, thesoftening or the finishing of textiles, in particular polyester-basedtextiles.

Another subject matter of the present invention is detergentformulations including of the order of 0.0l to 10%, preferably of theorder of 0.1% to 5% and very particularly of the order of 0.2 to 3%,with respect to the weight of said formulations, of said terephthalicpolyester composition forming the subject matter of the invention.

Another subject matter of the invention is the use of said terephthalicpolyester composition as soil-release agent in detergent formulationsfor the washing of textile articles, in particular textile articlesbased on polyester fibers.

Detergent formulations for the washing of textile articles, inparticular textile articles based on polyester fibers, which areparticularly advantageous with regard to their ecotoxicologicalproperties, are those including:

of the order of 0.01 to 10% by weight, preferably of the order of 0.1 to5% by weight, very particularly of the order of 0.2 to 3% by weight, ofthe soil-release terephthalic polyester composition (TPC) describedabove,

and of the order of 3 to 40% by weight, preferably of the order of 5 to35% by weight, of at least one anionic surface-active agent chosen fromsulfates of saturated aliphatic C₅-C₂₄ alcohols, optionally condensedwith approximately 0.5 to 30 mol of ethylene oxide,

not more than 5% by weight of said detergent formulation being able tobe composed of another type of anionic surface-active agent with lessadvantageous ecotoxicological properties, such as C₁-C₁₈alkylbenzenesulfonates.

Mention may be made, among the sulfates of optionally ethoxylatedalcohols which can be employed, of the sulfates of nonethoxylated C₈-C₁₈(preferably C₁₀-C₁₅) alcohols, the sulfates of C₅-C₁₃ (preferablyC₁₀-C₁₃) fatty alcohols condensed with approximately 1 to 30 (preferably1 to 10 mol) of ethylene oxide, or the sulfates of C₁₄-C₂₀ (preferablyC₁₄-C₁₈) fatty alcohols condensed with approximately 4 to 30 mol(preferably 4 to 10 mol) of ethylene oxide.

In addition to the soil-release terephthalic polyester composition (TPC)of the invention, other additives of the type of those described belowcan be. present in the detergent formulations.

SURFACE-ACTIVE AGENTS, in amounts corresponding to approximately 3-40%by weight with respect to the detergent formulation, surface-activeagents such as

Anionic Surface-active Agents

alkyl ester sulfonates of formula R—CH(SO₃M)—COOR′, where R represents aC₈-C₂₀, preferably C₁₀-C₁₃₆, alkyl radical, R′ a C₁-C₆, preferablyC₁-C₃, alkyl radical and M an alkali metal cation (sodium, potassium orlithium), a substituted or unsubstituted ammonium (methyl-, dimethyl-,trimethyl- or tetramethylammonium, dimethylpiperidinium, and the like)cation or a cation derived from an alkanolamine (monoethanolamine,diethanolamine, triethanolamine, and the like). Mention may veryparticularly be made of the methyl ester sulfonates for which the Rradical is a C₁₄-C₁₆ radical;

alkyl ether sulfates of formula ROSO₃M, where R represents a C₅-C₂₄,preferably C₁₀-C₁₈, alkyl or hydroxyalkyl radical, M representing ahydrogen atom or a cation with the same definition as above, and theirethoxylenated (EO) and/or propoxylenated (PO) derivatives exhibiting anaverage of 0.5 to 30, preferably of 0.5 to 10, EO and/or PO units;

alkylamide sulfates of formula RCONHR′OSO₃M, where R represents aC₂-C₂₂, preferably C₆-C₂₀, alkyl radical, R′ a C₂-C₃ alkyl radical, Mrepresenting a hydrogen atom or a cation with the same definition asabove, and their ethoxylenated (EO) and/or propoxylenated (PO)derivatives exhibiting an average of 0.5 to 60 EO and/or PO units;

salts of saturated or unsaturated C₈-C₂₄, preferably C₁₄-C₂₀, fattyacids, C₉-C₂₀ alkylbenzenesulfonates, primary or secondary C₈-C₂₂alkylsulfonates, alkylglycerol sulfonates, the sulfonated polycarboxylicacids disclosed in GB-A-1 082 179, paraffin sulfonates,N-acyl-N-alkyltaurates, alkyl phosphates, alkyl isethionates,alkylsuccinamates, alkylsulfosuccinates, the monoesters or diesters ofsulfosuccinates, N-acylsarcosinates, alkylglycoside sulfates orpolyethoxycarboxylates the cation being an alkali metal (sodium,potassium or lithium), a substituted or unsubstituted ammonium residue(methyl-, dimethyl-, trimethyl- or tetramethylammonium,dimethylpiperidinium, and the like) or a residue derived from analkanolamine (monoethanolamine, diethanolamine, triethanolamine, and thelike);

Nonionic Surface-active Agents

polyoxyalkylenated (polyethoxyethylenated, polyoxypropylenated orpolyoxybutylenated) alkylphenols, the alkyl substituent of which isC₆-C₁₂, comprising from 5 to 25 oxyalkylene units; mention may be made,by way of example, of Triton X-45, Triton X-114, Triton X-100 or TritonX-102, sold by Röhm & Haas Co.;

glucosamide or glucamide;

glycerolamides derived from N-alkylamines (U.S. Pat. No. 5,223,179 andFR-A-1 585 966);

polyoxyalkylenated C₈-C₂₂ aliphatic alcohols comprising from 1 to 25oxyalkylene (oxyethylene or oxypropylene) units; mention may be made, byway of example, of Tergitol 15-S-9 or Tergitol 24-L-6 NMW, old by UnionCarbide Corp., Neodol 45-9, Neodol 23-65, eodol 45-7 or Neodol 45-4,sold by Shell Chemical Co., or Kyro EOB, sold by The Procter & GambleCo.;

the products resulting from the condensation of ethylene oxide with ahydrophobic compound resulting from the condensation of propylene oxidewith propylene glycol, such as the Pluronics sold by BASF;

the products resulting from the condensation of ethylene oxide, thecompound resulting from the condensation of propylene oxide withethylenediamine, such as the Tetronics sold by BASF;

amine oxides, such as (C₁₀-C₁₈ alkyl)dimethylamine oxides or (C₈-C₂₂alkoxy)ethyldihydroxyethylamine oxides;

the alkylpolyglycosides disclosed in U.S. Pat. No. 4,565,647;

C₈-C₂₀ fatty acid amides;

ethoxylated fatty acids;

ethoxylated fatty amides;

ethoxylated amines.

Cationic Surface-active Agents

alkyldimethylammonium halides.

Amphoteric and Zwitterionic Surface-active Agents

alkyl dimethyl betaines, alkyl amidopropyldimethyl betaines, alkyltrimethyl sulfobetaines, or the condensation products of fatty acids andof protein hydrolysates.

ADJUVANTS FOR IMPROVING THE PROPERTIES OF SURFACE-ACTIVE AGENTS(builders), in amounts corresponding to approximately 5-50%, preferablyto approximately 5-30%, by weight for the liquid detergent formulae orto approximately 10-80%, preferably 15-50%, by weight for the powderdetergent formulae, builders such as

Inorganic Adjuvants (Builders)

alkali metal, ammonium or alkanolamine polyphosphates(tripolyphosphates, pyrophosphates, orthophosphates orhexametaphosphates);

tetraborates or borate precursors;

silicates, in particular those exhibiting an SiO₂/Na₂O ratio of theorder of 1.6/1 to 3.2/1, and the lamellar silicates disclosed in U.S.Pat. No. 4,664,839;

alkaline or alkaline earth carbonates (bicarbonates orsesquicarbonates);

cogranules of hydrated alkali metal silicates and of alkali metalcarbonates (sodium carbonate or potassium carbonate) which are rich insilicon atoms in the Q2 or Q3 form, which are disclosed in EP-A-488 868;

crystalline or amorphous alkali metal (sodium or potassium) or ammoniumaminosilicates, such as zeolites A, P, X, and the like; zeolite A with aparticle size of the order of 0.1-10 micrometers is preferred.

Organic Adjuvants (Builders)

water-soluble polyphosphonates (ethane-1-hydroxy-1,1-diphosphonates,salts of methylenediphosphonates, and the like);

water-soluble salts of carboxyl polymers or copolymers or theirwater-soluble salts, such as:

polycarboxylate ethers (oxydisuccinic acid and its salts, tartratemonosuccinic acid and its salts, or tartrate disuccinic acid and itssalts,

hydroxypolycarboxylate ethers;

citric acid and its salts, mellitic acid or succinic acid and theirsalts;

salts of polyacetic acids (ethylenediaminetetraacetates,nitrilotriacetates or N-(2-hydroxyethyl)nitrilodiacetates);

(C₅-C₂₀ alkyl)succinic acids and their salts (2-dodecenylsuccinates orlaurylsuccinates);

polyacetal carboxylic esters;

polyaspartic acid, polyglutamic acid and their salts;

polyimides derived from the polycondensation of aspartic acid and/or ofglutamic acid;

polycarboxymethylated derivatives of glutamic acid or of other aminoacids.

BLEACHING AGENTS, in amounts of approximately 0.1-20%, preferablyapproximately 1-10%, by weight, optionally in combination with BLEACHINGACTIVATORS, in amounts of approximately 0.1-60%, preferably ofapproximately 0.5-40%, by weight, agents and activators such as

Bleaching Agents

perborates, such as sodium perborate monohydrate or tetrahydrate;

peroxygenated compounds, such as sodium carbonate peroxohydrate,pyrophosphate peroxohydrate, urea hydrogen peroxide, sodium peroxide orsodium persulfate;

 preferably in combination with a bleaching activator generating insitu, in the detergent medium, a peroxycarboxylic acid; mention may bemade, among these activators, of tetraacetylethylenediamine,tetraacetylmethylenediamine, tetraacetylglycoluryl, sodiump-acetoxybenzenesulfonate, pentaacetylglucose, octaacetyllactose, andthe like;

percarboxylic acids and their salts (known as “percarbonates”), such asmagnesium monoperoxyphthalate hexahydrate, magnesiummeta-chloroperbenzoate, 4-nonylamino-4-oxoperoxybutyric acid,6-nonylamino-6-oxoperoxycaproic acid, diperoxydodecanedioic acid, thenonylamide of peroxysuccinic acid, or decyldiperoxy-succinic acid.

These agents can be used in combination with at least one of thesoil-release or antiredeposition agents mentioned hereinbelow.

Non-oxygenated bleaching agents, which act by photoactivation in thepresence of oxygen, can also be mentioned, agents such as sulfonatedzinc and/or aluminum phthalocyanines.

ANTIREDEPOSITION AGENTS, in amounts of approximately 0.01-10% by weightfor a powder detergent composition and of approximately 0.01-5% byweight for a liquid detergent composition, agents such as:

ethoxylated monoamines or polyamines, or polymers of ethoxylated amines(U.S. Pat. No. 4,597,898, EP-A-11 984);

carboxymethylcellulose;

sulfonated polyester oligomers obtained by condensation of isophthalicacid, of dimethyl sulfosuccinate and of diethylene glycol (FR-A-2 236926);

polyvinylpyrollidones;

iron- and magnesium-CHELATING AGENTS, in amounts of the order of0.1-10%, preferably of the order of 0.1-3%, by weight, agents such as

aminocarboxylates, such as ethylenediaminetetraacetates,hydroxyethylethylenediaminetriacetates or nitrilotriacetates;

aminophosphonates, such as nitrilotris(methylenephosphonates);

polyfunctional aromatic compounds, such as dihydroxydisulfobenzenes.

POLYMERIC DISPERSING AGENTS, in an amount of the order of 0.1-7% byweight, in order to control the calcium and magnesium hardness, agentssuch as:

water-soluble salts of polycarboxylic acids with a molecular mass of theorder of 2000 to 100000, obtained by polymerization or copolymerizationof ethylenically unsaturated carboxylic acids, such as acrylic acid,maleic acid or anhydride, fumaric acid, itaconic acid, aconitic acid,mesaconic acid, citraconic acid or methylenemalonic acid, and veryparticularly polyacrylates with a molecular mass of the order of 2000 to10000 (U.S. Pat. No. 3,308,067) or copolymers of arylic acid and ofmaleic anhydride with a molecular mass of the order of 5000 to 75000(EP-A-66 915);

poly(ethylene glycol)s with a molecular mass of the order of 1000 to50000.

FLUORESCENCE AGENTS (BRIGHTENERS), in an amount of approximately0.05-1.2% by weight, agents such as derivatives of stilbene, pyrazoline,coumarin, fumaric acid, cinnamic acid, azoles, methinecyanines,thiophenes, and the like (“The Production and Application of FluorescentBrightening Agents”, M. Zahradnik, published by John Wiley & Sons, NewYork, 1982).

FOAM-SUPPRESSANT AGENTS, in amounts which can range up to 5% by weight,agents such as:

C₁-C₂₄ fatty monocarboxylic acids or their alkali metal, ammonium oralkanolamine salts, or fatty acid triglycerides;

saturated or unsaturated, aliphatic, alicyclic, aromatic or heterocyclichydrocarbons, such as paraffins or waxes;

N-alkylaminotriazines;

monostearyl phosphates or monostearyl alcohol phosphates;

polyorganosiloxane oils or resins, optionally combined with silicaparticles.

SOFTENERS, in amounts of approximately 0.5-10% by weight, softeners suchas clays.

ENZYMES, in an amount which can range up to 5 mg by eight, preferably ofthe order of 0.05-3 mg, of active enzyme/g of detergent composition,enzymes such as proteases, amylases, lipases, cellulases or peroxidases(U.S. Pat. Nos. 3,553,139, 4,101,457, 4,507,219 and 4,261,868).

OTHER ADDITIVES, such as:

alcohols (methanol, ethanol, propanol, isopropanol, propanediol,ethylene glycol or glycerol);

buffer agents;

fragrances;

pigments.

The following examples are given by way of illustration.

Characteristics of the Terephthalic Polyester Composition (TPC) Prepared

These are determined by:

1) Size exclusion chromatography (SEC), using a size exclusionchromatography device of Waters type equipped with two-fold detection(RI and UV) and equipped with 3 columns, using N,N-dimethyl-acetamide(DMAc) comprising 10-2 mol/l of LiBr as eluent at 100° C.

 100 μl of a 1% by weight solution of polymer in the DMAc/LiBr mixtureare injected.

 The UV spectrum makes it possible:

to detect the presence of the aromatic A (terephthalic) nuclei,

to determine the percentage of ethylene terephthalate homooligomer(PET₁) in the terephthalic polyester composition (TPC),

the signal of the ethylene terephthalate homooligomers (PET₁) appearsbetween 1000 and 5000 (mass expressed in polystyrene equivalent);

the signal of the block terephthalic copolymers (PET₂/TE-POE) appearsbetween 5000 and 100000.

 The percentage of ethylene terephthalate homooligomer (PET₁) in theterephthalic polyester composition (TPC) is equal to the [area of thesignal of the ethylene terephthalate homooligomers (PET₁)/total area ofthe signals] ratio×100 (see the spectra in FIGS. 1/2 and 2/2,corresponding respectively to the products of example 1 and ofcomparative example 2).

to determine the weight-average molar mass of the block terephthaliccopolymer (PET₂/TE-POE), expressed in polystyrene equivalents.

2) Proton nuclear magnetic resonance (¹H NMR), by dissolution under warmconditions of the samples to be analyzed in a CDCl3/deuteratedhexafluoroisopropanole/deuterated trifluoroacetic anhydride mixture. TheNMR analysis is subsequently carried out at ambient temperature on aBrucker spectrometer at 300 MHz. The chemical shifts are expressed withrespect to hexamethylenedisiloxane.

 The chemical shifts corresponding to

aromatic (terephthalic T) nuclei,

oxyethylene units,

mono(oxyethyleneoxy) (OEO) residues present in the oxyethylene aromaticdiester (OAD) groups,

polyoxyethylene terephthalate blocks (TE-POE),

units at the end of chains, are given in the table below.

Chemical shifts in ppm Groups 8.03 T

4.68 OEO in OAD Ph—CO—O—CH₂—CH₂—O—CO—Ph 4.47 TE—POEPh—CO—O—CH₂—CH₂—O—PEG 4.04 End of chains Ph—CO—O—CH₂—CH₂—OH 3.88 End ofchains PEG—O—CH₂—CH₂—OH 3.65 Oxyethylene PEG—O—CH₂—CH₂—O—PEG

The molar percentage of each species is subsequently estimated from theintegral of the protons of each type of unit and then the percentages bymass are deduced therefrom. A working example is given in the followingtable with reference to the spectrum corresponding to the product ofexample 1.

The concentration by mass of [PET₁]+[PET₂/TE-POE]% w/w (i.e. 12.2% w/w)and the concentration by mass of the PhC(O)—O—CH₂—CH₂—O—C(O)—Ph units(i.e. 1.37% w/w) are obtained.

molar masse Integrals s of read on the the proton molar % by product ofexample 1 units spectrum % mass O_(1/2)-CO-Ph-CO-O_(1/2) 148 1 2.959.21* Ph-CO-O_(1/2)-O_(1/2)CH₂-CH₂-O_(1/2)-O_(1/2)-CO-Ph 44 0.5 1.481.37 Ph-CO-O_(1/2)-O_(1/2)CH₂-CH₂-O_(1/2)-O_(1/2)-PEG 44 0.915 2.70 2.50PEG-O_(1/2)-O_(1/2)CH₂-CH₂-O_(1/2)-O_(1/2)-PEG 44 30.155 88.97 82.55PEG-O_(1/2)-O_(1/2)CH₂-CH₂-OH 53 1.28 3.78 4.22Ph-CO-O_(1/2)-O_(1/2)CH₂-CH₂-OH 53 0.045 0.13 0.15 33.895 100 *Thecontent of TE with respect to [PET₁] + [PET₂/TE-POE], that is to saywith respect to (TPC), is calculated from this value.

Soil-release Properties

Detergent formula employed:

parts by Detergent composition weight zeolite 4A 25 light carbonate 15disilicate R2A 5 acrylic/maleic copolymer Sokalan CP5 5 (BASF) Nasulfate 10.7 carboxymethylcellulose 1 perborate monohydrate 15tetraacetylethylenediamine 5 linear dodecylbenzenesulfonate 6 SynperonicA3 (C₁₂-C₁₅ fatty alcohol 3 ethoxylated with 3 EO Synperonic A9 (C₁₂-C₁₅fatty alcohol 9 ethoxylated with 9 EO enzyme Esperase 4.0 T 0.3soil-release agent

Test

Prewashing

Squares lacking harshness, with dimensions of 10×10 cm,

of polyester Style 777 100% Dacron Type 54 (Disperse Dyeable),manufactured by Touzart and Matignon,

and of polyester/cotton (67/33), manufactured by CFT (Center For Testmaterials),.

are prewashed in a Tergotometer for 20 min at 40° C. with the detergentformula comprising 0.5% by weight of active material of soil-releasepolymer tested; the water used exhibits a hardness of 30° HT; the amountof detergent employed is 5 g per 1 l of water.

The squares of fabrics are subsequently rinsed 3 times for 5 min in coldwater (14° C.) and then dried by two passes under a glazing machine.

Staining

4 drops of dirty motor oil (DMO) are deposited on the prewashed testspecimens.

In order to ensure that the stains are firmly attached, the fabrics areplaced in an oven at 60° C. for 1 hour.

In order to make possible good reproducibility of the results, thefabrics are washed within 24 hours.

Washing

The washing is carried out under the same conditions as the prewashing(at 40° C. for 20 min, using 5 g of detergent comprising 1% of activematerial of soil-release polymer per 1 l of water of 30° HT, then 3rinsings of 5 min in cold water and 2 drying operations under a glazingmachine).

Evaluation

The reflectance of the fabrics before and after washing is measuredusing the Dr. Lange/Luci 100 calorimeter.

The effectiveness as soil-release agent of the polymer tested isassessed by the % of removal of the stains, calculated by the formula:

E in %=100×(R3−R2)/(R1−R2)

R1 representing the reflectance, before washing, of the unsoiled fabric;

R2 representing the reflectance, before washing, of the soiled fabric;

R3 representing the reflectance, after washing, of the soiled fabric.

The mean of the % of removal of the stains is calculated for eachproduct tested.

EXAMPLE 1

The various operations which follow are carried out in a stainless-steelreactor with a capacity of 1 l equipped with a stirrer of the helicalribbon type, with a jacket for the circulation of a heat-transfer fluidand with a distillation column:

1) 530 g of polyoxyethylene glycol with a molar mass of 3350 areintroduced at ambient temperature; the temperature is increased; whenthe latter reaches 130° C., 72.3 g (i.e. 12% by weight with respect tothe mixture) of polyethylene terephthalate Cleartuf 7202C from Shell,with a molar mass of 55000, and 0.37 g of magnesium oxide are added.

2) The temperature of the mixture is maintained at 130° C. for 5 min andthe mixture is subjected to several. degassings (placing under a slightexcess nitrogen pressure, followed by placing under vacuum), followingwhich a nitrogen headspace is retained and the temperature of thereaction mass is gradually increased to 272° C. over 3 h and 30 min.

3) The pressure in the reactor is then rapidly reduced to 66661 Pa (500mm of Hg) and maintained at this value for 20 min, during which thetemperature of the reaction mass is gradually brought to 284° C.

4) The pressure is subsequently further reduced to reach 200 Pa (1.5 mmof Hg) over approximately 1 h. These conditions are maintained for 1 hand the polymer formed is recovered.

The characteristics of the polymer obtained, defined by gel exclusionchromatography and by proton nuclear magnetic resonance, are given intable 1.

Comparative Example 2

The operations described in stages 1) to 3) of example 1 are repeated.The reaction mixture is subsequently maintained [operation 4′)] for 2 hand 30 min at 284° C. under 66661 Pa (500 mm of Hg).

The characteristics of the polymer obtained, defined by gel exclusionchromatography and by proton nuclear magnetic resonance, are given intable 1.

EXAMPLE 3

The operations 1) to 4) of example 1 are repeated, starting from thefollowing charges:

530 g of polyoxyethylene glycol with a molar mass of 3 350

87.5 g of polyethylene terephthalate (i.e. 14% by weight) with a molarmass of 55 000.

The characteristics of the polymer obtained, defined by gel exclusionchromatography and by proton nuclear magnetic resonance, are given intable 1.

Comparative Example 4

The operations 1) to 4′) of example 1 are repeated, starting from thefollowing charges:

530 g of polyoxyethylene glycol with a molar mass of 3350

87.5 g of polyethylene terephthalate (i.e. 14% by weight) with a molarmass of 55000.

The characteristics of the polymer obtained, defined by gel exclusionchromatography and by proton nuclear magnetic resonance, are given intable 1.

EXAMPLE 5

The operations 1) to 4) of example 1 are repeated, starting from thefollowing charges:

512.5 g of polyoxyethylene glycol with a molar mass of 3350

105 g of polyethylene terephthalate (i.e. 17% by weight) with a molarmass of 55 000.

The characteristics of the polymer obtained, defined by gel exclusionchromatography and by proton nuclear magnetic resonance, are given intable 1.

Comparative Example 6

The operations 1) to 4′) of example 2 are repeated, starting from thefollowing charges:

512.5 g of polyoxyethylene glycol with a molar mass of 3350

105 g of polyethylene terephthalate (i.e. 17% by weight) with a molarmass of 55000.

The characteristics of the polymer obtained, defined by gel exclusionchromatography and by proton nuclear magnetic resonance, are given intable 1.

Comparative Example 7

The operations 1) to 4′) of example 2 are repeated, starting from thefollowing charges:

500.2 g of polyoxyethylene glycol with a molar mass of 3 350

117.3 g of polyethylene terephthalate (i.e. 19% by weight) with a molarmass of 55000.

The characteristics of the polymer obtained, defined by-gel exclusionchromatography and by proton nuclear magnetic resonance, are given intable 1.

SEC chromatography data ¹H NMR data Content Molar PhCOOCH₂ Removal ofmass TE CH₂OCOPh of the Product of oligomer Mw % structures stainsexample * ** *** **** % 1 5 47 700 11.9 1.37 75 2, comparative 14 19 48711.7 0.95 63 3 6 41 000 13.3 1.53 73 4, comparative 21 13 100 13 1.35 705 5 54 200 16.2 1.83 71 6, comparative 22 17 900 16.2 2.02 69 7,comparative 25 16 800 17.3 2.31 64 *amount of (TE) units of (PET₁) withrespect to all the (TE) units present in (TPC). ***weight of (TE) unitsas % with respect to the total weight of (TPC) ****Ph: 2,4-phenylene

What is claimed is:
 1. A terephthalic polyester composition (TPC),comprising, as a mixture a polyethylene terephthalate homooligomer(PET₁) consisting essentially of oxyethylene terephthalate (TE) repeatunits of formula (I): —C(O)—A—C(O)—O—CH₂—CH₂—O—  (I) wherein Arepresents the 1,4-phenylene group, and a block terephthalic copolymer(PET₂/TE-POE) comprising: at least one polyethylene terephthalate block(PET₂) composed of oxyethylene terephthalate (TE) repeat units offormula (I) —C(O)—A—C(O)—O—CH₂—CH₂—O—  (I) wherein A represents the1,4-phenylene group, and at least one polyoxyethylene terephthalateblock (TE-POE) of formula: —C(O)—A—C(O)—O—CH₂—CH₂—O—(CH₂—CH₂—O)_(n)— allthe (TE) units present in said (TPC) composition represent at least 11%by weight of the weight of said (TPC) composition, said (TPC)composition presenting mono(oxyethyleneoxy) (OEO) residues of formula:_(1/2)O—CH₂—CH₂—O_(1/2) said (OEO) residues belonging to the oxyethylenearomatic diester (OAD) groups of formula: —A—C(O)—O—CH₂—CH₂—O—C(O)—A— present in all the (PET₁) and (PET₂) blocks, and wherein the value of nof the polyoxyethylene terephthalate block (TE-POE) of formula:—C(O)—A—C(O)—O—CH₂—CH₂—O—(CH₂—CH₂—O)_(n)—  is such that said blockexhibits a number-average molecular mass of 3 000 to 4 000, the (TE)units of the polyethylene terephthalate (PET₁) does not represent morethan 7% by weight of all the (TE) units present in the terephthalicpolyester composition (TPC), all the (TE) units present in said (TPC)composition represent from 11.5 to 17% by weight, of the weight of said(TPC) composition, the mono(oxyethyleneoxy) (OEO) residues of formula:_(1/2)O—CH₂—CH₂—O_(1/2)  represents from 1.3 to 2.3% by weight, of theweight of said terephthalic polyester composition (TPC), and theweight-average molar mass of said block terephthalic copolymer(PET₂/TE-POE) is at least 40
 000. 2. A composition as claimed in claim1, wherein the ends of the chains of homooligomers (PET₁) are composedof —C(O)—A—C(O)—O—CH₂—CH₂—OH units.
 3. A composition as claimed in claim1, wherein the ends of the chains of block terephthalic copolymer(PET₂/TE-POE) are composed of —C(O)—A—C(O)—O—CH₂—CH₂—OH units or—(CH₂—CH₂—O)_(n−1)—CH₂—CH₂—OH units.
 4. A process for the preparation ofa composition as defined in claim 1, comprising the steps of: a)carrying out a transesterification/condensation reaction of a reactionmixture comprising a polyethylene terephthalate with a weight-averagemolecular mass of 3000 to 4000 and a polyethylene glycol with anumber-average molecular mass of 1 500 to 4 000, according to apolyethylene terephthalate/(polyethylene terephthalate+polyethyleneglycol) ratio by mass of 11.5/100 to 17/100, and adding the polyethyleneterephthalate to the molten polyethylene glycol, then b) heating thereaction mixture under an inert atmosphere to a temperature of 100 to150° C., and adding a catalytic effective amount of magnesium oxide tothe reaction mixture, c) bringing the temperature of the mixture to atemperature of 250 to 290° C., and d) subsequently gradually placingsaid reaction mixture under vacuum to a pressure of less than 70 000 Pa,while optionally adjusting the temperature of said mixture to a value of250 to 290° C.
 5. A process according to claim 4, wherein: in step a)the weight-average molecular mass of the polyethylene terephthalate isfrom 10 000 to 80 000, and the number-average molecular mass of thepolyethylene glycol is from 3 000 to 4 000, the polyethyleneterephthalate/(polyethylene terephthalate+polyethylene glycol) ratio bymass is from 11.5/100 to 17/100, in step b) the reaction mixture isheated to a temperature of 120 to 130° C., and in step c) thetemperature of the mixture is brought to a temperature of 270 to 285°C., and, in step d), the pressure is between 7 000 to 130 Pa, whileoptionally adjusting the temperature of said mixture to a value of 270to 285° C.
 6. The process according to claim 4, wherein the amounts ofmagnesium oxide is from 20 to 500 ppm.
 7. The process according to claim6, wherein the amounts of magnesium oxide is from 100 to 350 ppm.
 8. Theprocess according to claim 4, wherein the reaction mixture furthercomprises an alkali metal organic salt.
 9. The process according toclaim 8, wherein the alkali metal organic salt is sodium acetate. 10.The process according to claim 8, wherein said salt is present accordingto an amount of 20 to 500 ppm.
 11. The process according to claim 10,wherein the amount is of 100 to 350 ppm.
 12. A process for washing,rinsing, softening or finishing textiles comprising treating saidtextiles with a detergent formulation comprising a composition asdefined in claim 1 used as a soil-release agent.
 13. A process accordingto claim 12, wherein said textiles are polyester-based textiles.
 14. Aprocess according to claim 12, wherein said formulation comprises from0.01 to 10% of said composition with respect to the weight of saiddetergent formulation.
 15. A process according to claim 14, wherein saidformulation comprises from 0.2 to 3% of said composition.
 16. Adetergent formulation comprising 0.01 to 10% of a composition as definedin claim 1 with respect to the weight of said detergent formulation. 17.A detergent formulation comprising 0.2 to 3% of a composition as definedin claim 1.